1. Field of the Invention
The present invention relates to an image-coding apparatus and image-coding method, data-coding apparatus and data-coding method, data-recording apparatus and data-recording medium, and in particular, the present invention relates to an image-coding apparatus and image-coding method for coding moving images, a data-coding apparatus and data coding method for coding input data that contains moving images and corresponding sound data, and a data-recording apparatus that includes the data-coding apparatus and data-recording medium on which an image-coding program or data-coding program is recorded.
2. Description of the Related Art
Conventionally, the contents of a program obtained from a broadcast signal are recorded on a recording medium such as videotape.
However, up until now, two programs that were broadcast during the same time period were not recorded simultaneously.
Moreover, when using conventional recording equipment for recording two different programs at the same time, it was necessary to use two systems for coding the moving images. This led to the problem of the need for high-cost recording equipment with complicated construction, as well as the need for employing a special recording method, which in turned required that a special reproduction method be used for reproduction.
In view of the problems described above, it is the object of the present invention to provide an image-coding apparatus and image-coding method, a data-coding apparatus and data-coding method, and a data-recording apparatus and data-recording medium, which contains a recorded image-coding program or data-coding program, that will make it possible to simply record two or more programs simultaneously, as well as use a conventional reproduction method for reproducing the recorded programs.
The above object of the present invention can be achieved by an image coding apparatus of the present invention, which codes moving images by coding a composite frame image that is obtained by fanning a boundary between and by connecting the respective frame images of a plurality of different moving images. The image coding apparatus is provided with: a motion-prediction-compensation device for independently performing motion prediction compensation for each of said frame images in said composite frame image; a quantization device for performing quantization for each of said frame images based on the results of said motion prediction compensation that is performed for each said frame image; a coding device for coding said moving images by coding each said frame image based on the results of said quantization that is performed for each said frame image; and a control device for controlling said motion-prediction-compensation device, quantization device and coding device such that said motion prediction compensation, quantization and coding are performed for a plurality of continuous composite-frame images by said motion-prediction-compensation device, quantization device and coding device, respectively.
According to the present invention, frame images, having a plurality of moving images, are collected together as a composite frame image, and the coding process is executed for each individual frame, and thus it is possible to code a plurality of moving images simultaneously with a single coding apparatus. In addition, since each frame image in one composite frame image is coded individually, it is possible to decode the coded moving image using a conventional decoding method.
In one aspect of the present invention, the motion-prediction-compensation device executes said motion prediction compensation by setting a search area for said motion prediction compensation within only the range of said frame images contained in said composite frame image, and detecting the motion vector.
According to this aspect in the motion-prediction-compensation process, movement vectors are detected by setting a search area that is within only the range of frame images of the composite frame image, so it is possible to code a plurality of moving images at the same time using the same coding method as used for a non-composite moving image.
In another aspect of the present invention, the quantization device independently performs said quantization for each of said frame image in said composite frame image.
According to this aspect, the quantization process is performed independently for each frame image, so it is possible to perform quantization accurately for each frame image.
In further aspect of the present invention, the image-coding apparatus is further provided with a discrete cosine transform device for performing discrete cosine transform of each said frame image based on the results of said motion prediction compensation that is performed on each said frame image, wherein said quantization device performs said quantization for each of said frame image of which discrete cosine transform is performed.
According to this aspect, discrete-cosine-transform processing is performed for each frame image, so it is possible to code each moving image with a high coding rate.
In further aspect of the present invention, the motion prediction compensation, quantization process and coding process are executed according to Moving Picture Experts Group (MPEG) format.
According to this aspect, it is possible to compress and code a plurality of moving images simultaneously.
The above object of the present invention can be achieved by a data-coding apparatus of the present invention, which includes an image-coding apparatus for coding moving images by coding a composite frame image that is obtained by forming a boundary between and by connecting the respective frame images of a plurality of different moving images. The image-coding apparatus is provided with: a motion-prediction-compensation device for independently performing motion prediction compensation for each of said frame images in said composite frame image; a quantization device for performing quantization for each of said frame images based on the results of said motion prediction compensation that is performed for each said frame image; a coding device for coding said moving images by coding each said frame image based on the results of said quantization that is performed for each said frame image; and a control device for controlling said motion-prediction-compensation device, quantization device and coding device such that said motion prediction compensation, quantization and coding are performed for a plurality of continuous composite-frame images by said motion-prediction-compensation device, quantization device and coding device, respectively. The data-coding apparatus is provided with: a separation device for separating moving images and sound data from a plurality of input data that contain said moving images and said sound data that correspond to said moving images; a first composite-image device for reducing the amount of data in said frame images of said separated moving images, and for generating said composite frame image to output that image to said image-coding apparatus; a sound-coding device for coding said separated sound data simultaneously with coding of the corresponding said moving images and for generating coded sound data; and a second composite-image device for combining corresponding said coded moving images and said coded sound data and for generating a plurality of said coded input data.
According to the present invention, the sound data is coded in parallel with coding of the moving images, after which, they are combined, and so it is possible to code a plurality of input data simultaneously. Therefore, it is possible to code a plurality of moving images simultaneously with simple construction, and when decoding the coded moving images it is possible to use a conventional decoding method as is.
The above object of the present invention can be achieved by a data-recording apparatus of the present invention, which includes an image-coding apparatus for coding moving images by coding a composite frame image that is obtained by forming a boundary between and by connecting the respective frame images of a plurality of different moving images. The data-recording apparatus is provided with: a motion-prediction-compensation device for independently performing motion prediction compensation for each of said frame images in said composite frame image; a quantization device for performing quantization for each of said frame images based on the results of said motion prediction compensation that is performed for each said frame image; a coding device for coding said moving images by coding each said frame image based on the results of said quantization that is performed for each said frame image; a control device for controlling said motion-prediction-compensation devices quantization device and coding device such that said motion prediction compensation, quantization and coding are performed for a plurality of continuous composite-frame images by said motion-prediction-compensation device, quantization device and coding device, respectively; a separation device for separating moving images and sound data from a plurality of input data that contain said moving images and said sound data that correspond to said moving images; a first composite-image device for reducing the amount of data in said frame images of said separated moving images, and for generating said composite frame image to output that image to said image-coding apparatus; a sound-coding device for coding said separated sound data simultaneously with coding of the corresponding said moving images and for generating coded sound data; a second composite-image device for combining corresponding said coded moving images and said coded sound data and for generating a plurality of said coded input data; and a recording device for separately recording said coded input data on a recording medium.
According to the present invention, it is possible to code and record a plurality of input data simultaneously. Therefore, it is possible to code and record input data from a plurality of sources simultaneously with simple construction, and when decoding and reproducing the recorded input data, it is possible to use conventional decoding and reproduction methods as are.
The above object of the present invention can be achieved by an image-coding method of the present invention for coding said moving images by coding a composite frame image that is obtained by forming a boundary between and by connecting the respective frame images of a plurality of different moving images. The image-coding method is provided with the processes of: independently performing motion prediction compensation for said frame images in said composite frame image; performing quantization for each of said frame images based on the results of said motion-prediction-compensation that is performed for each of said frame images; coding said moving images by coding each of said frame images based on the results of said quantization that is performed for each of said frame images; and repeating said motion prediction compensation, quantization and coding for a plurality of continuous said composite frame images.
According to the present invention, the frame images, which comprise a plurality of moving images, are combined into a composite frame image, and coding is performed for each image individually, so it is possible to code a plurality of moving images simultaneously with one coding apparatus. Moreover, since the frame images within a single composite frame image are coded individually, it is possible to decode the coded moving images using a conventional decoding method as is.
In one aspect of the present invention, the process of independently performing motion prediction compensation executes said motion-prediction-compensation by setting a search area for said motion-prediction-compensation within only the range of said frame images that are included in one said composite frame image and detecting the motion vectors.
According to this aspect, in the movement-prediction-compensation process, movement vectors are detected by setting a search area that is within only the range of frame images of the composite frame image, so it is possible to code a plurality of moving images at the same time using the same coding method as used for a non-composite moving image.
In another aspect of the present invention, the process of performing quantization independently performs quantization for each of said frame images in said composite frame image.
According to this aspect, the quantization process is performed independently for each frame image, so it is possible to perform quantization accurately for each frame image.
In further aspect of the present invention, the image-coding method is further provided with: the process of performing discrete cosine transform for each of said frame images based on the results of said movement-prediction-compensation that is performed for each of said frame images, and wherein said process for performing quantization executes quantization for each of said frame images after discrete cosine transformation.
According to this aspect, discrete-cosine-transform processing is performed for each frame image, so it is possible to code each moving image with a high coding rate.
In further aspect of the present invention, the motion prediction compensation, quantization and coding are executed based on MPEG format.
According to this aspect, it is possible to compress and code a plurality of moving images simultaneously.
The above object of the present invention can be achieved by a data-coding method of the present invention that includes the image-coding method for coding said moving images by coding a composite frame image that is obtained by forming a boundary between and by connecting the respective frame images of a plurality of different moving images. The image-coding method is provided wit the processes of: independently performing motion prediction compensation for said frame images in said composite frame image; performing quantization for each of said frame images based on the results of said motion-prediction-compensation that is performed for each of said frame images; and coding said moving images by coding each of said frame images based on the results of said quantization that is performed for each of said frame images; and repeating said motion prediction compensation, quantization and coding for a plurality of continuous said composite frame images. The data-coding method is provided with the processes of: separating moving images and sound data from a plurality of input data that includes said moving images and corresponding sound data; generating said composite-frame image to execute said image-coding method after reducing the amount of data in said frame images containing said separated moving images; coding each of separated said sound data simultaneously with coding of corresponding said moving images to generate coded sound data; and combining corresponding said coded moving images and said coded sound data to generate a plurality of said coded input data.
According to the present invention, the sound data is coded in parallel with coding of the moving images, after which, they are combined, and so it is possible to code a plurality of input data simultaneously. Therefore, it is possible to code input data from a plurality of sources simultaneously with simple construction, and when decoding the coded input data, it is possible to use a conventional decoding method as is.
The above object of the present invention can be achieved by a data-recording medium of the present invention on which an image-coding program is recorded so that it is readable by a computer, which is included in an image-coding apparatus that codes said moving images by coding a composite-frame image that is obtained by forming a boundary between and by connecting the respective frame images of a plurality of different moving images. The image-coding program causes the computer to function as: a motion-prediction-compensation device for independently performing a motion prediction compensation for each of said frame images in said composite frame image; a quantization device for performing quantization for each of said frame images based on the results of said motion prediction compensation that was performed for each said frame image; a coding device for coding said moving images by coding each said frame image based on the results of said quantization that was performed for each said frame image; and a control device for controlling said motion-prediction-compensation device, quantization device and coding device such that said motion prediction compensation, quantization and coding are performed for a plurality of continuous composite-frame images by said motion-prediction-compensation device, quantization device and coding device, respectively.
According to the present invention, the computer functions to combine a plurality of moving images of a frame image into a composite frame image and executes the coding process for each individually, so it is possible to code a plurality of moving images simultaneously with one coding apparatus. Moreover, the computer functions to code the frame images in one composite frame image individually, so it is possible to decode the coded moving images using a conventional decoding method as is.
In one aspect of the present invention, the motion-prediction-compensation device performs said motion prediction compensation by setting the search area for the motion-prediction-compensation within only the range of said frame images that are included in one said composite-frame image and detecting the motion vectors.
According to this aspect, the computer functions to detect movement vectors in the movement-prediction-compensation process by setting a search area that is within only the range of frame images of the composite frame image, so it is possible to code a plurality of moving images at the same time using the same coding method as used for a non-composite moving image.
In another aspect of the present invention, the quantization device performs quantization independently for each of said frame images in said composite-frame image.
According to this aspect, the computer performs quantization independently for each frame image, so it is possible to quantize each frame image accurately.
In further aspect of the present invention, the image-coding program further causes the computer to function as: a discrete cosine transform device for performing discrete cosine transformation of each of said frame images based on the results of said motion-prediction-compensation that is performed for each of said frame images, wherein said quantization device performs quantization for each of said frame images after discrete cosine transformation.
According to this aspect, the computer performs discrete cosine transform for each frame image, so it is possible to code each moving image with a high coding rate.
In further aspect of the present invention, the motion-prediction-compensation, quantization and coding are executed based on MPEG format.
According to this aspect, it is possible to compress and code a plurality of moving images simultaneously.
The above object of the present invention can be achieved by a data-recording medium of the present invention on which a coding program is recorded so that it is readable by a computer, which is included in a data-coding apparatus that includes an image-coding apparatus that codes said moving images by coding a composite-frame image that is obtained by forming a boundary between and by connecting the respective frame images of a plurality of different moving images. The coding program that includes an image-coding program causing the computer to function as said image-coding apparatus. The image-coding apparatus is provided with: a motion-prediction-compensation device for independently performing a motion prediction compensation for each of said frame images in said composite frame image; a quantization device for performing quantization for each of said frame images based on the results of said motion prediction compensation that was performed for each said frame image; a coding device for coding said moving images by coding each said frame image based on the results of said quantization that was performed for each said frame image; and a control device for controlling said motion-prediction-compensation device, quantization device and coding device such that said motion prediction compensation, quantization and coding are performed for a plurality of continuous composite-frame images by said motion-prediction-compensation device, quantization device and coding device, respectively. In addition, the coding program further causes the computer to function as: a separation device for separating moving images and sound data from a plurality of input data that includes said moving images and corresponding sound data; a first composite-image device for reducing the amount of data in said frame images containing said separated moving images, and for generating said composite-frame image to output that image to said computer functioning as said image-coding apparatus; a sound-coding device for coding each of separated said sound data simultaneously with coding of corresponding said moving images, and for generating coded sound data; and a second composite-image device for combining corresponding said coded moving images and said coded sound data, and for generating a plurality of said coded input data.
According to the present invention, the computer codes sound data in parallel with the coding of moving images, and then combines them, so it is possible to code a plurality of input data simultaneously. Therefore, it is possible to code input data from a plurality of sources simultaneously with simple construction, and when decoding the coded input data, it is possible to use a conventional decoding method as is.